Facebook has reportedly strengthened its partnership with Spotify. Spotify is a music streaming service that users can access on their PCs, Macs, iOS and Android devices. According to Forbes, a new Spotify music streaming service for Facebook is undergoing internal testing. A release date hasn’t been mentioned. Technically, there hasn’t even been an official announcement. If true, the deal appears to be mutually beneficial for both companies since no cash is involved.

As Forbes points out, Facebook’s partnership with Spotify will give the site another foothold in the world of entertainment. Facebook recently gave users the opportunity to rent Warner Bros. movies using Facebook Credits. With Spotify, Facebook users will be able to use the service for free (although it may be limited) or pay for a premium service. Spotify stands to attract a whole new base of customers once they start listening to music together.

The Facebook Spotify service will stream music onto the social network. It will apparently be prominently displayed on the left of the Facebook News Feed. Friends will also be able to listen to music together at the same time.

United States Facebook users should also get access to Spotify on Facebook eventually. Spotify just has to work out all the details with record labels.